Detachable bit for drills and the like



.July M, l936 J. R MacDoNELL l DETACHABLE BITVFR DRILLS AND THE LIKEFiled April 16, 1955 ,2 sheets-sheet 1 w A: A K4 JOM/ma v JUHV M w64 J.R5. MaeDoNELl.v v 2.,?,69

DETCHABLE BIT FOR DRILLS AND THE LIKE Filed April 16, 1935 2Sheets-SheerI 2 INVENTOR Attorney Patented July 14, 1936 UNTTED STATESPATENT OFFICE DETACHABLE BIT Fon DRILLS AND THE LIKE John RonaldMacDonell, Falconbridge,

Ontario, Canada Application April 16, 1,935, Serial No. 16,711

In Canada. February 20, 1935 4 Claims.V (01.255-164) from three to sixfeet of digging, while the drill shank is good for approximately 400 ft.to 600 ft. of digging before it crystallizes and has to be replaced. Itwill therefore, be apparent that it is essential to have a detachablebit that can be easily replaced, so that the drill shank can be retainedfor its full life.

Various detachable bits are in use at the present time, but, myinvention covers improvements in the construction of the bit and drillshank, and in the means for coupling them together.

The primary object of my invention is to provide a drill shank with adetachable bit, to lengthen the life of the drill.

A further object is a connection between bit and drill shank that issafe and reliable.

Another object is an easy means of coupling bit to drill shank withoutthe use of tools.

A further object is to prevent splitting or breaking of drill shank whenin use. f

A further object is to prevent drill shank and bit becoming locked `orriveted together.

A further object is to provide means for cooling bit when in operation,and for disposing of the water, dirt, etc., when digging.

With these and other objects in view that may be apparent as thedescription proceeds, the invention consists in the novel arrangement ofparts as hereinafter more specifically set forth, claimed and shown inthe accompanying drawings, forming a part of this present application,and in which- Fig. 1 is a side elevation of the drill and bit joinedtogether.

Fig, 2 is a perspective View of drill and bit being coupled together.

Fig. 3 is a side elevation of bit alone.

Fig. 4 is a perspective viewv of drill alone, showing one design forcoupling it with bit.

Fig. 5 is a perspective view of the reverse side of Fig. 4.

Fig. 6 is a side elevation of an alternative design for bit.

Fig. 'l is a perspective view of drill showing an alternative design forcoupling with bit.

Fig. 8 is a perspective View of the reverse side of Fig. 7.

Fig. 9 is a cross section View on Fig. 1, along lines 9 9.

Referring more in detail to the drawings in which similar referencecharacters designate corresponding parts, it will be seen that theinvention consists of A drill made in two sections, a drill shank I, anda bit 2. These two parts are coupled together by inserting one end ofthe drill shank I, inside the bit 2, through an opening 3, in the sideof bit 2. A right angle cut 4, on each side of drill shank slides over apair of small projections 5, inside the bit and the drill I, then slidesdown inside 10 the bit 2, into hollow portion 6.

A hole 'II runs the length of the drill I, to allow cooling water toflow through the bit, and opening 8, in bit 2 allows the water tocontinue to the face of the bit to cool it while cutting. A nitch Thedrill shank I, may be tapered slightly at one end. as at I2, or at bothends. By tapering the shank the bit will slide on easily and tighten upat the top after drilling for a time should the end of drill shankbecome knurled it will still remove easily.

The right angle cuts 4, are at both ends of the drill shank so that thebit 2 may be attached to either end. The four edges of drill shank arechamfered at I3.

It will be noted the distance between the cut 4 and end of the shank isgreater than the depth of the opening 3 and in order tol connect ordetach bit 2, the drill shank I has to be bent over at an angle toinsert or remove the shank from the side of the bit. There is no chanceof the bit coming off the drill while digging, as it is necessary tofirst pull the bit down and bend it over on an angle to allow theprojections 5 to slip'out of angle cuts 4.

An alternative style of bit is shown in Fig. 6. This bit is similar tothe other except the bottom is cut away on two sides, shown at I4, andsmall nitches I5, allow the water, dirt, etc., to by-pass up past thebit.

An alternative drill shank is illustrated in Figs. 'l and 8. This drillis similar` in construction except the cuts I6, on each side of shankand at both ends are in a V shape, with the opening pointing upward.This makes the connection with bit 2 even more secure so the drillcannot become detached from bit.

It will be seen from the foregoing that this novel method of connectingbit to drill is decided advantage in this type of drilling to insure asafe and convenient connection.

I claim:

1. In combination a drill shank for power drills with detachable cuttingbit, grooved indents, in the sides of said drill shank, cut diagonallydownward and joining vertical grooves, said grooves forming a dependableconnection with corresponding projections inside said cutting bitinterlocking said drill shank and bit, a tapered end on said drill shankinsuring easy removal of said bit, means for cooling cutting edge ofsaid bit, means for by-passing residue up past bit While drilling,substantially as described.

2. In combination, a drill shank for power drills having verticalgrooves in the sides thereof, intersecting lateral grooves openingthrough one edge of the shank, a bit having a socket to receive the endof said shank, said socket having an opening through the side thereoffor insertion of the shank in a lateral direction and projections on theWalls of the socket for interlocking engagement with the grooves of saidshank.

3. In combination, a` drill shank for power drills having verticalgrooves in the sides thereof closed at both ends and intersectinglateral grooves opening through one edge of the shank, a bit having acentral socket to receive the end of said shank, said socket having anopening Vthrough the side thereof for insertion of the shank in alateral direction and projections on the walls of the socket forinterlocking engagement with the grooves of said shank.

4. In combination, a drill shank for power drills having diagonalgrooved indents in the sides of said shank merging with verticalgrooves, a cutting bit having a socket to receive the end of said shankand projections in said socket for interlocking engagement With saidgrooves.

JOHN RONALD MACDONELL.

